1. Field Of The Invention
The present invention deals with the field of vacuum forming systems. More particularly the present invention deals with the field of devices utilized for vacuum forming of hot plasticized material such as vinyl drawn normally from an extruder and heated.
Heretofore most devices make use of pattern forms rotating on cylindrical drums which require excessive additional instrumentation due to the fact that the forming surface is arcuate rather than flat. The present invention provides a novel means for utilizing a flexibly resilient belt and a metallic woven support belt thereunder with both belts extending between rollers. A flexibly resilient pattern form is positioned on the flexible resilient belt which passes through a flat forming surface which includes all of the advantages and none of the disadvantages of the use of a cylindrical or arcuate forming surface.
2. Description Of The Prior Art
Prior art systems have been disclosed for vacuum forming or for continuous process forming such as U.S. Pat. No. 2,218,338 patented Oct. 15, 1940 to F. W. Manning on a Method and Apparatus For Making Filter Fabric; U.S. Pat. No. 2,855,653 patented Oct. 14, 1958 to E. Kastenbein on an Apparatus For Making Tile Panels; U.S. Pat. No. 3,099,043 patented Jul. 30, 1963 to E. C. Held, Jr. on a Method and Apparatus For Vacuum Forming Hollow Articles; U.S. Pat. No. 3,126,580 patented Mar. 31, 1964 to H. Paschke on an Apparatus For Continuously Deforming Thermoplastic Foils; U.S. Pat. No. 3,872,199 patented Mar. 18, 1975 to Lester V. Ottinger and assigned to Champion International, Corporation, on a Method of Manufacturing A Foamed Urethane Structural Product Having High and Low Density Portions; U.S. Pat. No. 3,895,087 patented Jul. 15, 1975 to L. Ottinger et al on a Method Of Manufacturing A Molded Composite Urethane Foam Structural Panel; U.S. Pat. No. 3,954,923 patented May 4, 1976 to E. Valyi on a Method Of Making Composite Plastic Article; U.S. Pat. No. 3,982,868 patented Sep. 28, 1976 to William R. Rinker and assigned to The B. F. Goodrich Company, on a Continuous MOld Thermo Forming; U.S. Pat. No. 4,009,975 T. Ninomiya et al on a Device For Producing An Obliquely Oriented Film Of Thermoplastic Synthetic Resin; U.S. Pat. No. 4,061,706 patented Dec. 6, 1977 to P. Duffield et al on a Process For The Continuous Melt Thermoforming Of Polymers; U.S. Pat. No. 4,128,369 patented Dec. 5, 1978 to William J. Kemerer et al and assigned to Hazelett Strip-Casting Corporation on a Continuous Apparatus For Forming Products Form Thermoplastic Polymeric Material Having Three-Dimensional Patterns And Surface Textures; U.S. Pat. No. 4,315,885 patented Feb. 16, 1982 to Jerome H. Lemelson on a Continuous Molding Apparatus and Method; U.S. Pat. No. 4,332,847 patented Jun. 1, 1982 to W. Rowland on a Method For Compression Molding Or Retroreflective Sheeting And Sheeting Produced Thereby; U.S. Pat. No. 4,352,771 patented Oct. 5, 1982 to Robert J. Szabo and assigned to Variform Plastics, Inc. on a Method and Apparatus For Creating Random Shadow Patterns in Formed Vinyl Sheet Article; U.S. Pat. No. 4,464,319 patented Aug. 7, 1984 to H. Halter et al on a Method Of And Apparatus For The Coiling Of Flattened Synthetic Resin Foil Tubes; U.S. Pat. No. 4,477,243 patented Oct. 16, 1984 to H. Wallsten on a Thermoforming Apparatus; U.S. Pat. No. 4,487,730 patented Dec. 11, 1984 to A. Larribe on a Process For Draping Layers Of Composite Materials; U.S. Pat. No. 4,495,135 patented Jan. 22, 1985 to L. White on a Method For Forming Container having Re-Entrant Flange; U.S. Pat. No. 4,582,666 patented Apr. 15, 1986 to I. Kenworthy et al on a Method And Apparatus For Making A Patterned Non-Woven Fabric; U.S. Pat. No. 4,634,358 patented Jan. 6, 1987 to H. Dellbrugge on an Apparatus For Flattening And Withdrawing Blown Continuous Plastic Tubular Films; U.S. Pat. No. 4,649,008 patented Mar. 10, 1987 to Thomas O. Johnstone, et al and assigned to Alcan Aluminum Corp. on a Method of Making Interlocking Vinyl Siding; U.S. Pat. No. 4,646,722 patented Apr. 14, 1987 to L. Armstrong on a Method Of Forming A Decorative Panel Of Molded Plastic; U.S. Pat. No. 4,657,625 patented Apr. 14, 1987 to H. Kawakami on an Apparatus For Producing Sheet Having Many Hollow Bodies From Thermoplastic Material; U.S. Pat. No. 4,702,877 patented Oct. 27, 1987 to L. Davis, Jr. on a Method For Molding Concrete Blocks Or Bricks; U.S. Pat. No. 4,776,998 patented Oct. 11, 1988 to P. Davidson et al on a Method For Making Refractory Shaped Articles By Cutting Vertically Hanging Extrudates and U.S. Pat. No. 4,847,034 patented Jul. 11, 1989 to K. Araki et al on a Vacuum Forming Method.
One of the main problems with prior art constructions, particularly such as U.S. Pat. No. 3,099,043, is the formation of seams. With rigid pattern forming members, they must separate while passing over the rollers. These pattern forms then rejoin for molding however a seam is forever present between adjacent sections during the vacuum forming due to the need to separate while passing around the rollers. The flexible pattern forming means of the present invention overcomes these problems in the prior art.